1. Field of the Invention
The present invention concerns a method to control the acquisition and/or evaluation procedure of image data in medical examinations of the type wherein, in a previously acquired planning image data set entirely or partially covering a target volume, location (spatial) information of the target volume is determined automatically using a statistical model of the target volume based on data about real anatomy, and the acquisition and/or evaluation procedure is controlled using the location information.
2. Description of the Prior Art
In serial examinations of pathologies or examinations of a possible medicinal effect on these pathologies, for the examiner it is extremely important to discover the precise orientation and positioning of the pathological object as quickly as possible. Since the resolution capability in small animal measurements is, for example, in the range of 100 μm and is in a range of half a millimeter in humans, prefabricated parameter sets cannot simply be adopted. Rather, the position and orientation of the subject to be examined must be rediscovered in every new examination. For this purpose, a planning image data set is typically acquired. The more precisely that the orientation of the subject to be examined should be determined, the greater the resolution of the planning image data set must be. If this panning image is three-dimensional, in magnetic resonance tomography acquisitions it is the case that, for doubled resolution in the phase coding directions, a measurement time that is twice as long must be scheduled. For a three-dimensional data set, two phase coding gradients are required, meaning that a doubled resolution in these two directions corresponds to a quadrupling of the measurement time. In addition, after this time-consuming acquisition, the positioning of the subject must still also be precisely determined by an operator in order to establish the parameter sets for subsequent acquisitions. An exact positioning of the measurement slice is therefore necessary since (for example in flow measurements) the measurement slice must be situated perpendicular to the vessel through which medium flows, because otherwise it artifacts can occur in the exposures. Such position determinations can thereby easily occupy half of the available measurement time. It is therefore desirable to be able to automatically and exactly register the position and orientation of the subject to be examined with an optimally low-resolution planning image data set.
DE 10 2006 017 932 A1 describes a method in which a target volume in a planning image data set is automatically determined using a statistical model of the target volume that is based on data about real anatomy, and the acquisition and/or evaluation operation is then controlled with this information. The statistical model is acquired by means of measurements on multiple test subjects.